Method and apparatus for stacking tortilla chips

ABSTRACT

A method and apparatus for stacking curved, triangular snack food chips, e.g., tortilla chips, for packaging in a sleeve-type container. The chips are fed into a first, U-shaped vibratory chute, which automatically causes the apex corners of the chips to extend beyond the opposing base edges of adjacent chips and which automatically orients the chips such that lines about which they are curved are oriented parallel to the longitudinal direction of the U-shaped chute. The chips are then fed into a W-shaped chute, with the chips facing in opposite directions falling automatically into opposite troughs of the W-shaped chute. The chips are then automatically reoriented by 120° such that their upturned apex corners point in the direction of travel, and the chips are stacked automatically as they slide up along one another in a shingled manner.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional of application Ser. No.09/326,682, filed Jun. 7, 1999 now U.S. Pat. No. 6,338,606.

FIELD OF THE INVENTION

The present invention relates generally to a method and apparatus forprocessing snack food chips. More particularly, the invention relates toa method and apparatus for stacking curved tortilla chips in a uniformstack which then can be packaged neatly and compactly, e.g., in acylindrical can or other sleeve-type container.

BACKGROUND OF THE INVENTION

Tortilla chips are one of the more popular types of snack food productsand have come to be associated with having a triangular shape.Additionally, snack food chips which are used for dipping, e.g., potatochips, tortilla chips, or corn chips, preferably are curved to enhancethe scooping ability of the chip as well as to add strength to the chip.

With respect to packaging, a stacked arrangement of snack food chips hasbeen found to be popular. The typical triangular shape of a tortillachip, however—particularly a curved tortilla chip—previously hasprevented tortilla chips from being packaged in a stacked arrangement inan efficient, automatic process.

SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for automaticallyarranging curved, triangular snack food chips such as tortilla chips ina neat, compact, stacked arrangement which is suitable for packaging thechips in a cylindrical can or other sleeve-type package. According tothe invention, the chips are transported along a vibrating U-shapedchute, oriented in an alternating arrangement. The vibrating U-shapedchute automatically ensures both proper orientation and positioning ofthe chips in that the chips slide laterally such that their centers ofgravity are at the bottom of the chute and such that base edges of thetriangular chips are oriented parallel to the longitudinal axis of theU-shaped chute. The chips then fall into a W-shaped vibrating chute,with the chips originally having one orientation automatically beingcaused to fall into the trough constituting one half of the W-shapedchute and the chips having the opposite orientation automatically beingcaused to fall into the other trough constituting the other half of theW-shaped chute.

The chips then travel along the W-shaped chute by sliding along theirbase edges, i.e., with their opposite, upturned apices pointingperpendicular to the direction of travel of the chips. The tortillachips are then caused to rotate by 120° such that the upturned apices“lead” as the chips continue to progress. This configuration permits thechips to slide into nested, stacked relationship automatically, in whicharrangement the chips can be packaged easily in a stacked configuration.

Thus, in a first aspect, the invention features a method of stackingcurved, generally triangular tortilla chips for subsequent packaging,e.g., in a sleeve-type package. The method entails transporting asuccession of the chips along a direction of travel, and whiletransporting the chips, causing them to be oriented such that their apexcorners point in the direction of travel. The chips are then caused tobecome stacked automatically by virtue of the apex corner of one chipsliding up and over the base edge of the preceding chip in thesuccession such that they come into a stacked, nested arrangementautomatically.

In preferred embodiments, the chips are oriented properly by slidingdown a J-slide from one conveyor to another. Alternatively, the chipscan be allowed to tumble over the end of the first conveyor onto thesecond conveyor.

In another aspect, the invention features a method of segregating thechips into separate lines or successions of chips based on the directionin which the chips point (as indicated by their upturned, apex corners).The method entails transporting the chips in a given direction of traveland causing the chips to be oriented such that the line about which eachis curved is substantially parallel to the direction of travel. Thechips are also caused to move laterally, relative to the direction oftravel, such that their centers of gravity become generally aligned.(This may be done simultaneously with the step of causing the chips tobe oriented such that their lines of curvature are substantiallyparallel.) At this point, the straight base edges of the chips pointingin one direction will all be aligned, and the straight base edges of thechips pointing in the opposite direction will all be aligned, and theapex corners of the chips pointing in one direction will extendlaterally beyond the base edges of the chips facing in the oppositedirection and vice-versa. The chips are then segregated into twoseparate conveyor troughs by being tripped or partially flipped by meansof their apex corners into the troughs, with the chips pointing in onedirection going to one conveyor trough and the chips pointing in theother direction going to the other conveyor trough.

In preferred embodiments, the chips are both oriented and caused to movelaterally simultaneously by transporting them along the bottom of avibrating U-shaped chute, the radius of curvature of which preferablymatches the radius of curvature of the chips. Additionally, the conveyortroughs are provided by means of a W-shaped chute, and the chips aretripped or partially flipped into one side of the “W” or the other.

In combination, these two aspects provide a method of segregating andstacking curved, generally triangular chips such as tortilla chips.

In another aspect, the invention features an apparatus for segregatingand stacking for subsequent packaging a succession of curved, generallytriangular chips. The apparatus features a first, vibratory, generallyU-shaped conveyor chute which feeds into a second, generally W-shapedconveyor chute. The W-shaped conveyor chute has means for rotating thechips by about 120°, and the apparatus includes two accumulatorconveyors which receive chips from the W-shaped conveyor chute and whichautomatically accumulate and stack the chips in a nested, stackedarrangement.

In preferred embodiments, the first, U-shaped conveyor chute includes apair of fingers extending from its downstream end, and the fingers arepositioned above the two troughs of the second, W-shaped conveyor chuteto trip or flip the chips into one trough or the other depending on theorientation of the chips. Additionally the W-shaped chute preferably isvibratory, as are the accumulator conveyors. The means for rotating thechips can be J-slides which transfer the chips from the troughs of theW-shaped chute to the accumulator conveyors or, alternatively, the chipscan be allowed to tumble over the edge of the end of the W-shaped chuteonto the accumulator conveyors.

By employing the various inventive concepts disclosed herein, it ispossible to produce curved, triangular chips such as tortilla chips inalternating directions (which is the most efficient way to make tortillachips) and then stack them automatically, conveniently, and reliably tobe packaged in a popular sleeve-type container.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail in connection withthe drawings, in which:

FIGS. 1 and 2 are a plan view and a side view, respectively, of acurved, triangular tortilla chip to be packaged using the method andapparatus of the invention;

FIG. 3 is a plan view of the upstream portion and part of the middleportion of the apparatus of the invention, and

FIG. 3a is a plan view of the relevant portion of an alternativeconfiguration thereof;

FIGS. 4 and 5 are section views of the apparatus shown in FIG. 3 takenalong the lines 4—4 and 5—5, respectively;

FIG. 6 is a plan view of the downstream end of the middle portion of theapparatus of the invention where it joins the upstream end of thedownstream-most portion of the apparatus of the invention;

FIGS. 7 and 8 are a side view and an end view, respectively, taken alongthe lines 7—7 and 8—8, respectively, in FIG. 6 and showing the J-slideused to transfer the tortilla chips from the middle portion to the endportion of the apparatus of the invention and simultaneously tore-orient them;

FIG. 9 is an “edge-on” side view illustrating the endmost portion of theapparatus of the invention, at which point the tortilla chips areautomatically being stacked;

FIG. 10 is a section view illustrating the endmost portion of theapparatus as shown in FIG. 9, taken along the line 10—10 therein;

FIGS. 11 and 12 are side views, analogous to FIG. 7, showing alternateembodiments of the apparatus of the invention; and

FIG. 13 is a section view taken along the lines 13—13 in FIG. 12.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As shown in FIG. 1, a tortilla chip 10 customarily has an equilateraltriangular shape. Moreover, as shown in FIG. 2, tortilla chipspreferably have a certain amount of curvature, which can be imparted tothe chips by frying or baking in a curved mold. It will be appreciatedthat the two edges of the triangle 12 and 14 will be curved, whereas theopposite, “included” edge will be straight. For purposes of describingthe invention, the straight edge will be referred to as the base edge B,and the opposite corner of the triangle will be referred to as the apexA.

Furthermore, it will be appreciated that because the chip is anequilateral triangle, its center of gravity 16 will be located one-thirdof the distance between the base and the apex. Additionally, assumingthe tortilla chip has a circular arc of curvature, it will be curvedabout a line or axis of curvature 20. With this configuration andnomenclature, it will be understood that if one were to lay one of thecurved tortilla chips on a table, it could rock on its “back” surface 22(FIG. 2), and if one were to press the base edge B down against thetable, the apex A would be upturned.

In general, because of their triangular shape, tortilla chips can be(and generally are) cut from a dough sheet in an alternating pattern,i.e., with the apex corners facing in alternating directions. (As aresult, there is no “lace” between successive tortilla chips, and thishelps to reduce wasted dough.) With the invention, tortilla chips soproduced can be kept in such an alternating arrangement, which lookslike the four leftmost chips shown in FIG. 3, as the chips aretransferred out of their cooking molds.

After they are cooked, the curved, triangular tortilla chips 10 aretransferred from their molds to a generally U-shaped, vibrating chute 30(FIG. 3), the upstream end 32 of which is slightly higher than thedownstream end 34. Preferably, the radius of curvature of the inner,concave surface 36 of the U-shaped chute matches the radius of curvatureof the convex, “back” surface 22 of the tortilla chips 10. The tortillachips may be transferred from the cooking apparatus into the U-shapedchute 30 either automatically or by hand, whichever is more convenient.If transferred automatically, the chips will be arranged relativelyuniformly, as are the four leftmost chips shown in FIG. 3; if, on theother hand, the chips are transferred to the chute by hand, they willtend to be oriented and positioned somewhat more randomly, as are themiddle two chips shown in FIG. 3. Regardless of how the chips aretransferred to the U-shaped chute 30, the invention has been found towork quite well.

As the U-shaped chute vibrates, the tortilla chips will move downstream,from left to right as shown in FIG. 3, because the upstream end 32 islocated slightly higher than the downstream end 34. Moreover, becausethe center of gravity of each chip is closer to the base edge B than itis to the apex A, the chips will slide transversely relative to thelongitudinal axis of the U-shaped chute such that their centers ofgravity move to the bottom of the chute, as illustrated at the right endof the U-shaped chute in FIGS. 3 and 4. This causes a lateral ortransverse “segregation” of the chips such that the apices A of thechips are laterally offset relative to the base edges B of adjacentchips, as shown at the downstream end 34 of the U-shaped chute.Moreover, because the curvature of the U-shaped chute preferably matchesthe curvature of the tortilla chips, the tortilla chips also will orientthemselves automatically such that the base edges B are alignedsubstantially parallel to the longitudinal axis of the U-shaped chute30, i.e., with the line 21 (FIG. 1) passing through the center ofgravity 16 and parallel to the base edge of the chip aligned over andextending along the bottom of the trough 30. This feature isparticularly advantageous when the chips are loaded into the chute 30 ina manner which does not result in them being as aligned as might bedesired, e.g., by hand.

After they are laterally segregated and properly oriented, the tortillachips drop from the U-shaped chute 30 into a W-shaped chute 40. As shownin FIGS. 3 and 5, a pair of fingers 42 extend slightly from thedownstream end of the U-shaped chute over the two troughs 44, 46 whichare formed by the two halves of the W-shaped chute 40. As shown in FIG.5, the fingers 42 are attached to the convex, undersurface of theU-shaped chute, e.g. by welding, and they are laterally spaced such thatthe apices of the laterally separated tortilla chips “hang up” on thefingers as the chips slide off of the downstream end 34 of the U-shapedchute and drop into the W-shaped chute 40, as illustrated by the chipshown in dashed lines in FIG. 3. As a result, the chips are “flipped”slightly over the vertex 48 of the W-shaped chute, and theyautomatically fall alternatingly into the opposite troughs 44 and 46.Thus, all chips having their apices facing in one direction fall intoone of the troughs, and all chips having their apices facing in theopposite direction fall into the other trough. The chips slide downalong the slanted inner walls 50 of the W-shaped chute, and their baseedges B butt up against the sidewalls 52 with the apices positioned nearthe vertex 48 of the W-shaped chute. See FIG. 5.

As an alternative to the fingers 42, the U-shaped chute may simply havea rectangular notch 43 cut out of the downstream end of it, as shown inFIG. 3a. In that case, the U-shaped chute, per se, would extend slightlyover the upstream end 54 of the W-shaped chute 40.

Like the U-shaped chute 30, the W-shaped chute 40 vibrates, and itsupstream end 54 (see FIG. 3) is elevated slightly relative to itsdownstream end 56 (see FIG. 6). Accordingly, the tortilla chips slidealong the slanted inner walls 50 from left to right as shown in FIGS. 3and 6. Because the tortilla chips are oriented with their apicespointing up, however, such that they move transverse relative to thedirection in which the apices “point”, they can not be stackedautomatically at this point.

As I have discovered, part of the key to being able to stack curvedtriangular tortilla chips automatically is to orient them such that theapices “lead” as the chips travel downstream. Accordingly, it isnecessary to rotate the tortilla chips 120° relative to the orientationthey have in the W-shaped chute. This is accomplished easily,effectively, and reliably by means of the structure illustrated in FIGS.6-8.

In particular, at its downstream end 56, the W-shaped chute splits, andeach trough thereof terminates in a J-slide 60 which leads the tortillachips to generally straight (i.e., longitudinally extending), V-shapedvibratory accumulator conveyors 62. As the chips reach the downstreamend of the W-shaped chute, they slide down the J-slides 60 onto theaccumulator conveyors 62.

The tortilla chips slide down the J-slides with their base edges Bagainst the sidewalls 52 of the W-shaped chute 40 and, as illustrated,they rotate as they slide down. This results in the tortilla chipslanding against upstanding guide walls 66 of the accumulator conveyors62 with what had been their “leading” corners L (FIG. 6) striking theguide walls first, but with the tortilla chips now rotated byapproximately 90°. As the tortilla chips slide all the way down alongthe slanted support walls 68 and come to rest against the guide walls66, they continue to rotate about the previously leading corners L andcome to rest against the guide walls 66 with their apices A now rotated120° forward (relative to the direction of travel of the chips). Thus,the apices A now point in the direction in which the chips aretraveling.

Because the upstream ends 70 of the accumulator conveyors 62 (see FIG.6) are slightly higher than the downstream ends 71 (see FIG. 9), thetortilla chips will move from left to right as shown in FIGS. 6, 7, and9 as the accumulator conveyors vibrate. As shown in FIG. 9—which is an“edge-on” view looking straight down along the slanted support wall 68of the top accumulator conveyor of the two shown in FIG. 6 (as indicatedby the arrows 9—9) and showing the accumulation of tortilla chips at thedownstream end thereof—the tortilla chips move along the slanted supportwall 68 of each accumulator conveyor until they reach end wall 72 at thedownstream end 71 of the accumulator conveyor.

Because the apices, which are now leading, are upturned, the firsttortilla chip to reach the end wall 72 will slide up along the end wall72 such that it is resting on its base edge B with its apex A pointingup. As the next tortilla chip slides into the first tortilla chip,because its apex corner A is upturned, it will slide into and up alongthe concave, front surface of the tortilla chip in front of it and it,too, will come to stand on its base edge B. In this manner, all of thetortilla chips automatically will “shingle” themselves and slide into anested, stacked arrangement, as shown at the downstream end 71 of theaccumulator conveyor 62.

In addition to re-orienting the tortilla chips by 120° such that theirapices lead as the chips travel along the accumulator conveyors 62, itis also key to the success of my invention to maintain this orientation;the V-shaped construction and orientation of the accumulator conveyorsensures that this requirement is met. In particular, because the supportwalls 68 are slanted relative to horizontal as seen in section in FIG. 8(in addition to being slanted slightly relative to horizontal from theupstream end of the accumulator conveyor to the downstream end), thetortilla chips will slide down along them until they come to restagainst the upstanding guide walls 66 (which define the V-shapedcross-section in conjunction with the support walls 68) with the curvededges extending between the previously leading corners L and the apicesA (see FIG. 6) resting flush against the guide walls 66. (The chips areshown in FIG. 6 as spaced slightly from the guide walls 66; this is forclarity only.) Because the edges rest flush against the guide walls 66and the weight of the chips keeps them there, the tortilla chips areunable to spin or rotate as they vibrate along the length of theaccumulator conveyors and the required, apex-first orientation necessaryfor automatic stacking is ensured. (Were the vibratory accumulatorconveyors simply flat sheets, the curved or upturned shape of thetortilla chips would make them particularly prone to spinning because,in that case, the chips would make contact with the conveyors only alongthe line of tangency between their convex back surfaces 22 (FIG. 2) andthe conveyors.)

Preferably, the angle φ between the guide walls 66 and the support walls68 (see FIG. 8) is on the order of 65°, i.e., slightly larger than thecorner angles of the tortilla chips. (See FIG. 10.) This angle helps tomaintain the proper orientation for the chips to “shingle up” onthemselves, and because the angle is only slightly wider than the cornerangle of the tortilla chips, it keeps the chips aligned and orientedproperly for subsequent packaging while at the same time allowing aslight amount of “play,” which is important to prevent chip breakage.

Once an appropriate amount of tortilla chips have been so stacked, theyare packaged by suitable packaging means (not shown), e.g., an apparatuswhich can load the tortilla chips into a cylindrical can or othersleeve-type container. As an additional benefit of the invention, thetortilla chips once again will automatically start to shingle themselvesinto proper stacked arrangement for further packaging—without the needfor operator intervention—after the process has been interrupted forsuch packaging (or for some other reason). This is in contrast to otherautomatic food product stackers, such as cracker stackers, which requirean operator to intercede and re-start the stacking process every (ornearly every) time it is interrupted.

It will be appreciated that one may depart from the embodiment of theinventive method and apparatus discussed above without departing fromthe scope and spirit of the invention. For example, it will be observedfrom FIG. 6 that the overall width of the conveying line approximatelydoubles when the line transitions from the W-shaped chute to the twoaccumulator conveyors. On a commercial scale set-up of the invention, itis contemplated that there could be as many as thirty-six to forty-eightsuch lines; accordingly, the amount of floor space taken up by theaccumulators could be large.

To conserve floor space, rather than J-slides 60, the downstream end ofthe W-shaped chute could terminate abruptly, as shown in FIG. 11. Inthat case, the tortilla chips would simply be permitted to rotate by120° as they tumble over the downstream-most bottom edge 41 of theW-shaped chute and onto the accumulator conveyor 62. If this approach isused, it is recommended that the angle θ between the inner slanted walls50 of the W-shaped chute (see FIG. 5) be decreased such that the chipsassume more of an upright, standing-on-end configuration to ensure thatthey spin around their centers of gravity as they fall off the end ofthe W-shaped chute.

If one desired more control over the tumbling chips but still wished toachieve the space savings of the embodiment shown in FIG. 11, one couldmaintain the J-slides at the downstream end of the W-shaped chute butdecrease the angle θ to approximately 5° to 10° such that the tortillachips are standing straight up as they enter the J-slide portion. Inthat case, as illustrated in FIGS. 12 and 13, it is suggested thatretaining tongues 63 be fastened in place, spaced slightly from theinner slanted walls 50 of the W-shaped chute, to form a narrow gap orpassageway 65 through which the chips slide down onto the accumulatorconveyors and to prevent the chips from falling off of the W-shapedchute by tumbling over the side walls 52.

Moreover, although the invention has been described and illustratedabove using a tortilla chip production run in which the tortilla chipsenter the U-shaped chute 32 in alternating fashion, i.e., with theapices of the tortilla chips pointing toward one side of the U-shapedchute and then the other in alternating fashion, this is not necessaryfor obtaining the benefit of the invention. For example, the tortillachips could be stacked after passing through a seasoning apparatus inwhich they are relatively spread out, and the seasoning apparatus wouldthen feed the tortilla chips onto the U-shaped chute 30. In that case,it will be appreciated that the chips will have a rather randomorientation pattern in the chute. Alternatively, it is conceivable thattortilla chips could be fed into the U-shaped chute 30 with just asingle orientation, i.e., with all apex corners A facing the samedirection. In that case, all chips would fall into the same trough 44 or46 of the W-shaped chute and would be stacked on a single accumulatorconveyor.

Other modifications likely will occur to those having skill in the artand are deemed to be within the scope of the following claims.

We claim:
 1. An apparatus for segregating and stacking for subsequentpackaging a succession of curved, generally triangular chips, theapparatus comprising: a first, vibratory, generally U-shaped conveyorchute for transporting the chips and having an upstream end and adownstream end; a second, generally W-shaped conveyor chute comprisingtwo troughs, said second conveyor chute having an upstream end and adownstream end, the upstream end of the second conveyor chute beingpositioned to receive chips from the downstream end of the firstconveyor chute and configured to receive chips into either of saidtroughs for transport thereby; means for rotating the chips by about120° in a plane about their centers of gravity; two accumulatorconveyors which automatically accumulate and stack the chips in anested, stacked arrangement, each of the two accumulators beingpositioned to receive chips from one of the two troughs of the W-shapedconveyor chute.
 2. The apparatus of claim 1, further comprising a pairof fingers extending from the downstream end of the first, U-shapedconveyor chute and positioned above the two troughs of the second,W-shaped conveyor chute to trip or flip each of the chips into onetrough or the other depending on the orientation of each of the chips.3. The apparatus of claim 1, wherein the downstream end of the first,U-shaped conveyor chute has a notch disposed above the upstream end ofthe second, W-shaped conveyor chute and configured to trip or flip eachof the chips into one trough or the other depending on the orientationof each of the chips.
 4. The apparatus of claim 1, wherein the second,W-shaped conveyor chute is vibratory.
 5. The apparatus of claim 1,wherein the accumulator conveyors are vibratory.
 6. The apparatus ofclaim 1, wherein the means for rotating the chips comprise J-slideswhich transfer the chips from the troughs to the accumulator conveyors.7. The apparatus of claim 1, wherein the means for rotating the chipscomprise a lower edge of the downstream end of the second, W-shapedconveyor chute and wherein the downstream end of the second, W-shapedconveyor chute is positioned sufficiently above the accumulatorconveyors that the chips rotate by approximately 120° as they tumbleover said lower edge and onto the accumulator conveyors.